Current-transformer.



L. M SCHMIDT CURRENT TRANSFORMER.

APPLICATION FILED SEPT. 11, 1908.

1,022,880. Patent ed Agm 9, 1912.

3 5 L w j WITNEEIJEZI INVENTEIRZ M PW 57 7 LULlifi MSBHMHJT ATTY.

"UNITED STATES LOUIS M. SCHMIDT,

PATENT OFFICE.

OF LYNN, MASSACHUSETTS, ASSIGNOR. TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK.

CURRENT-TRANSFORMER.

Specification of Letters Patent.

Patented AprQQ, 1912.

Application filed September 11, 1908. Serial No. 452,576.

citizen of the United States, residing at Lynn, county of Essex, Stateof Massachu setts, have-invented certain new and useful Improvements inCurrent-Transformers, of which the following is a specification.

This invention relates to apparatus for transforming electric currentsby induction between two interlinked conductors, and hase'specialreterence to what are called .current -t-ransformers forproducing currents of small volume for use in meters and other Theobject of my invention is to provide :1

current transformer in which the primary can be so connected as to giveone ratio with heavy currents and another ratio with lower currents; insuch fashion that the instruments may be read directly in. either case.

A further object is to provide a strong and compact constructiondispensing with Wires in the primary winding, and utilizing said primaryas a support for the secondary coil and the connecting rod and linkshereinafter described.

To these ends, the invention consists in a current transformer havingits primary winding composed of a stout bar divided longitudinally intopreferably two sections, suitably insulated from each other, with meansfor connecting said sections in series or in parallel, at will. On thisbar is mounted the secondary coil, and to 1ts ends are. at-

tached not only the line terminals or bus bars, but also the linksorblocks which sup port the connecting rod used to connect the sections inseries.

. The specific features of novelty will ap pear from the followingdetailed descrip tion and claims. taken in connection with .heaccompanying drawing, in wnieh$ It is customary to build such' Figure 1is a perspective view of a current transtornier embodying n'iyanvention,Fig. 2 is a diagram showing the transformer with the two sections of the)rimarvconnectedin series, Fig. 3 is a diagram showing said sectionsconnected in multiple, Fig. 4 is an end view of the arrangement shown inFig. 1 and Fig. 5 is an end view showing the sections of the primaryconnected in multiple.

The secondary coil is shown at 1, concen- .trio with the primarywinding, which con preferably of two parallel lengths or sections 2insulated from each other. A convenient mode of construction is thatshown in Figs. 1 and 4, where two semicylindrical bars are laid on eachside of a strip 4 of insulation, thus forming a stout bar dividedlongitudinally into sections suitably insulated from each other. At op-'posite ends of said bars there are wide flattened portions 5 5 formingline terminals. The other ends of the bars are preferably flattenedalso, to facilitate the attachmentthereto of links 6 G by means of whichthe bars may be connected to a rod 7 running parallel with the barsoutside of the coil 1. Spacers 8 of insulating material connect said rodwith the terminals 5 5.

\Vhen connected as shown in Figs. 1, 2 and 4, the two bars are inseries, the circuit being from line to the terminal 5, and thence by wayof the bar 2 and link 6 to the rod 7, link (3, bar 3 and terminal 5' toline.

In Figs. and 5, the rod 7, links 6, 6 and spacers 8 are omitted, and aU-shaped clip 9 is secured over each end of the sectional primary, thusconnecting the two bars 2 3 in parallel.

The construction can be modified to a considerable extent withoutdeparting from the spirit or scope of my invention.

\Vhat I claim as new and desire to secure by Letters Patent of theUnited States, is,

1. A current transformer having a primary winding composed of a stoutbar divided longitudinally into sect-ions with insulation between thesections, a connecting rod parallel with said bar, links for connectingsaid bar sections and rod in series,

and a secondary winding in inductive rela sulation between them, asecondary coil supwith said bar, and links for connecting said ported onsaid bin; and devices connecting sections and rod in series. 10 said barsections and also supported thereby. In witness whereof I have hereuntose 3. A current transformer having a primy hand this fifth day ofSeptember, 1908. mary Winding consisting of a stout bar di- LOUIS M.SCHMIDT. vicled longitudinally into sections with in- Witnesses:sulation between them, a secondary coil sup- JOHN A. MoMANUs, J12,

ported on said bar, a connecting rod parallel CHARLES A. BARNARD.

